Preparation of diaminoanthraquinone sulfonic acids



United States Pat t.

PREPARATION OF DIAMINOANTHRAQUINONE SULFONIC ACIDS Albert-Bloom, Summit, and Leslie M; Schenck, Westfield, N; 1., assignors to General Aniline & FilmCorporation, New York, N. Y., a corporation of" Delaware No Drawing. Application May 22 1956;

a Serial No. 586,383

9 Claims: (Cl.260--371) The invention here presented is a procedure for the sulfonation of diaminoanthraquinone by the basic steps of forming a diaminoanthraquinone sulfate then suspending the sulfate in an inerthigh-boiling liquid andvheating the material to complete the conversion to sulfonate.

The aminoanthraquinone sulfonates inlgeneral are materials. of considerable value as intermediates for dyestufiis, pharmaceuticals and thelike, and the monoaminoanthraquinone isreadily sulfonated by a very simple treatment with sulfuric acid, either by baking, or by heating in solution, to give a satisfactory yield of the sulfonate. However all of. the procedures used for the monoamine fail when applied to the diamines. Mostof. the procedureswhich work'well with themonoa'mine,

destroy the diamine so that no' yield of the desired product is obtained. Apparently thevsulfonation of the.di-'* amines is much more ditficult than the sulfonation of the monoamines, seemingly'because' ofthe' presence of the second amino substituent,.and the second amino substit-. uent materially weakens the stability of the anthraquinone" molecules. Accordingly it appears that'at'the necessary temperatures for sulfonation, the potent "destructive effect ofstrong sulfuric acid, and the weaker molecular structure of the diamines together cause a fairly. complete destruction of the-molecule.' f

It is now found however that if a monosulfate of the diamine is first formed, so that there is no free sulfuric,

acidto exert its destructive action; the sulfate is suspended in an inert high-boiling liquid diluent, to permit of rapid circulation ofthe mixture during'heating, Whereby hot spots are avoided, itbe'comes' then'possibleto sulfonate, not directly, but by a shift-ofthesulfur-oxygen" radical from the position of sulfate of the amino-group, to a position of sulfonate in the ring portion of the mole culeir This procedure permits the use of a substantially lower temperature, permits the prompt and easy removal oft-he water of condensation and thus avoids the destruction of the primary portion of the molecule, since the temperature of'reaction is lowand there is no free acid; and" in addition the water is-eliminated as fast "as formed, preventingthe developmentof' an equilibrium condition.

The reaction is primarily applicable to the 1,5'-diamino-' anthraquinones since'these are the more important; Hawever,-it is also equally 'applicable'to the 1,4-diamino anthraquinones and in each instance" a yield of 60% or better of the' desired compound is obtained, the yield frequentlybeing -better than' 90% and with carefulhandling, almost a 100% yield isobtainable. In addition. there is relatively little contamination ofthe inert'carf rierdiluent, and it maybe reused for successive batches 65 maybe reused, without purification orother treatment, I for the processing of fromlO' to 20 batches of the diwith only minor treatmenti. That is, the inert diluent amino sulfate, and when the'amounts ofimpuritiesdo become sufliciently great to interfere withthe' reaction, a

simple fractional distillation is suificient to the inert liquid for reuse.

2,842,564 7 Patented July 8, 195 8 The present procedure is applicable to the monoamino anthraquinones; and it yields an excellentproduct. How'- ever it offers little?advantage'in'themaking of themonoamine 'sulfo'nate over prior processes; its principalyalue is" in i 1 the --manufacture' of the Y i polyaminoanthraquinone sulfonates, for i which purpose it gives 1 yields far betterthan any other process andis much-simpler, cheaper 'an'df more effective than any of' the" prior procedures 'sug' gestedi T i I Not only is the process applicable to all of'the diamenoanthra'quinones, but itis also -applicable= to' hi'ghjer aminoanthra'quinones; Whilethe trian1inoanthraquinones" and. tetraminoanthraquinones are-possible, theyare -at the present time chemical curiosities and have -no'commercial use. Nonetheless the present process is etficiently applicable to \the .sulfonation of. such compounds? H in the reaction. The matter of'-'purity does not appear to he. of great, importance, except. insofaras. impurities present in the raw material .tend to remain in theinert: diluent, unless their: boiling points.:are.;1ower than; the reaction temperature, which. is 'the. case. with enough of the impurities, to, give a substantial purifying-etfect.v

Similarly the sulfuric acid may be of: anyconvenient purity and it does not appear. that the presence ofwsmall quantities of the heavy metals or. other minorimpurities is of importance;-.that,is, the ordinary. commercial gradev of acid, either chamber acid, or catalyst acidis.-satisfaC-- tory j' It is however desirable thata fairly strongiacidibe used, :to avoid dilution oftthe diaminoantbraquinonersul fate .with unnecessary amounts of water. I

A third component is a high boiling inert diluent which may be trichlorobenzene or may be hexamethylbenzene,

' hex'achlorobenzene, tribi'omob'enzene, decalin, or petroleum mineral oils, etch. V p

In practicing the invention, an. appropriate amount 0f; the diarr'iinoanthraquinone is, weighed. out, anda moleeu-- lar amount. of sulfuric acid,.preferably as the monohy-i drate, or with -a minimum of. contained water, is then addedto the diaminoanthraquinone and the mixture well stirred, until a homogeneous diarninoanthraquinone sulfate is obtained. This reaction is preferably. conducted at a relatively low temperature, and the acid may be' added in smalllportionaor. in a small stream toavoid an undue temperature rise. Miea'ntime the inert diluent is prepared in anappropriate reactor inwhich it can-be heated to a suitable temperature, usually in the neighbor hood "of 175 to 225 C. The polyaminoanthraquinona sulfate is then stirred into the inert diluent liquid to form a suspension or solution therein. A suflicient amount of. inert liquid is: used so 'that the resultis 'a thin slurry suitable for easy-stirring; The. temperature isthen raised to the reactionpoint and held at that pointfor a substantial number of hours; 1 At temperatures'in the neighborhood of 200 C.,. a length of time of the general order of magnitude of 16 hours. isfound tovbe suitable since this givesa nearlycornplete reaction. At; the end of this time the inert liquidis cooleditoroomi temperature and the sulfonate filtered E. Itmay be noted that a major portion of the by-products and impurities are either volatile at the reaction temperature, or are soluble in the inert liquid and accordingly a relatively 'very high purity is obtained in the sulfonate.

. It may be noted that the sulfonationyields a molecule due removed; the purified product being recovered by acid precipitation. Example 1 100 g. 1,5-diaminoanthraquinone sulfate (prepared by intimately mixing I-S-diaminoanthraquinone with a molar quality of sulfuric acid) is suspended in 720 g. trichlorobenzene. The reaction mixture is slowly distilled to remove water formed during the sulfonation, After 16 hours at ZOO-215 C., the product and unreacted 1-5-diaminoanthraquinone is filtered from the trichlorobenzene and slurried in 1930 g. water and 50 g. ammonia at 90- 95. The dissolved product is filtered free of unreacted starting material, and the filtrate precipitated by addition of hydrochloric acid. The crystalline 1,5-diaminoanthraquinone-Z-sulfonic acid is separated from the mother liquor by' filtration, water washed and dried at 85 C. Yield: 64.3 g. (68% of theory).

Example 2 100 g. 1,4-diatninoanthraquin0ne sulfate (prepared by intimately mixing 1,4-diaminoanthraquinone with a molar quality of sulfuric acid) is suspended in 720 g. trichlorobenzene. The reaction mixture is slowly distilled to remove water formed during the sulfonation. After 16 hours at ZOO-215 C., the product and unreacted 1,4-diaminoanthraquinone is filtered from the trichlorobenzene and slurried in 1930 g. water and 50 g. ammoniaat 90 95 The dissolved product is filtered free of unreacted starting material, and the filtrate precipitated by addition of hydrochloric acid. The crystalline 1,4-diaminoanthraquinone-sulfonic acid is separated'frorn the mother liquor by filtration, water washed and dried at 85 C. Yield: 64.3 g. (68% of theory).

Example 3 100 g. 1,8-diaminoanthraquinone sulfate (prepared by intimately mixing 1,8-diaminoanthraquinone with a molar quality ofsulfuric acid) is suspended in 720 g. trichlorobenzene. The reaction mixture is slowly distilled to remove water formed during the sulfonation. After 16 hours at 200-215 C., the product and unreacted 1,8-diaminoanthraquinone is filtered from the trichlorobenzene and slurried in 1930 g. water and 50 g. ammonia at 90- 95 C. The dissolved product is filtered free of unreacted starting material, and the filtrate'precipitated by addition of hydrochloric acid. The crystalline 1,8-diaminoanthraquinone-sulfonic acid is separated from the mother liquor by filtration, water washed and dried at 85 C. Yield: 64.3 g. (68% of theory).

Example 4 Example 1 was repeated using hexamethylbenzene in place of the suggested trichlorobenzene. The reaction proceeded equally wellto yield an excellent grade of 1,5-diaminoanthraquinone sulfonate.

Example 5 greatly facilitates the progress of- 4 Example 6 The procedure of Example 1 was repeated using a good grade of saturated high-boiling mineral oil having an initial boiling point of about 250 C. As before an excellent reaction and an excellent product was obtained.

Example 7 The procedure of Example 1 was repeated using a temperature range between 225 C. and 235 C. The reaction proceeded at a considerably higher rate of speed, and was substantially complete in 6 to 8 hours. However the yields were sharply lower and a good deal more decomposition occurred.

Thus the process of the invention permits of the formation of diaminoanthraquinone sulfonates in the absence of free sulfuric acid and at temperatures sufiiciently low to avoid thermal decomposition of the anthraquinone molecule.

While there are above disclosed but a limited number of embodiments of the process of the invention it is possible to provide still other embodiments without departing from the inventive concept herein disclosed, and it is therefore desired that only such limitations be imposed upon the appended claims as are stated therein or required by the prior art.

The invention claimed is:

1. A process for the production of polyaminoanthraquinone sulfonates comprising the steps in combination of forming a polyaminoanthraquinone sulfate suspending the sulfate in an inert high boiling liquid and heating the resulting sulfate to a temperature sufiiciently high to cause a molecular rearrangement to form the sulfonate from the sulfate, with a minimum of by-products and minimum destruction of the anthraquinone molecule.

2. A process for the production of polyaminoanthraquinone sulfonates comprising the steps in combination of forming a polyaminoanthraquinone sulfate in the absence of free sulfuric acid, suspending the resulting sulfate in a high boiling inert liquid andheating the resulting sulfate to a temperature sufiiciently high to cause the molecular rearrangement to form the sulfonate from the sulfate, with a minimum of by-products and minimum destruction of the anthraquinone molecule.

3. 'A process for the production of diaminoanthraquinone sulfonates, comprising the steps in combination of preparing a diaminoanthraquinone sulfate, suspending the sulfate in an inert high boiling liquid, and heating the suspension to a temperature between and 225 C.

4. A process for the production of polyaminoanthraquinone sulfonates, comprising the steps in combination of preparing a polyaminoanthraquinone sulfate in the absence of free sulfuric acid, suspending the sulfate in an inert high boiling liquid, and heating the suspension to a temperature between 175 and 225 C.

5. A process for the production of polyaminoanthraquinone sulfonates, comprising the steps in combination of preparing a polyaminoanthraquinone sulfate in the absence of free sulfuric acid, suspending the sulfate in an inert high boiling liquid, and heating the suspension to a temperature between 175 and 225 C., filtering out the reaction product, dissolving in water and filtering out unreacted and water-insoluble impurities.

6. A process for the production of polyaminoanthraquinone sulfonates, comprising the steps in combination of preparing a polyaminoanthraquinone sulfate in the absence of free sulfuric acid, suspending the sulfate in an inert high boiling liquid, and heating the suspension to a temperature between 175 and 225 C., filtering out the reaction product, dissolving in water and filtering out unreacted and water-insoluble impurities and precipitating the pure sulfonate by the addition of hydrochloric acid.

7. A process for the production of polyaminoanthraquinone sulfonates, comprising the steps in combination of preparing a polyaminoanthraquinone sulfate in the absence of free sulfuric acid, suspending the sulfate in an inert high boiling liquid comprising trichlorobenzene, and heating the suspension to a temperature between 175 and 225 C., filtering out the reaction product dissolving in water and filtering out unreacted and water-insoluble impurities and precipitating the pure sulfonate by the addition of hydrochloric acid. 7

8. A process for the production of polyaminoanthraquinone sulfonates, comprising the steps in combination of preparing a polyaminoanthraquinone sulfate in the absence of free sulfuric acid, suspending the sulfate in an inert high boiling liquid comprising hexamethylbenzene, and heating the suspension to a temperature between 175 and 225 C.,

filtering out the reaction product dissolving in water and filtering out unreacted and water-insoluble impurities and precipitating the pure sulfonute by the addition of hydrochloric acid.

9. A process for the production of polyaminoanthraquinone sulfonates, comprising the steps in combination of preparing a polyaminoanthraquinone sulfate in the absence of free sulfuric acid, suspending the sulfate in an inert high boiling liquid comprising high boiling mineral oil, and heating the suspension to a temperature between 175 and 225 C., filtering out the reaction product dissolving in water and filtering out unrencted and water-insoluble impurities and precipitating the pure sulfonate by the addition of hydrochloric acid.

References Cited in the file of this patent UNITED STATES PATENTS Davidson et a1 Aug. 23, 1932 Ogilvie Oct. 10, 1944 

1. A PROCESS FOR THE PRODUCTION OF POLYAMINOANTHRAQUINONE SULFONATES COMPRISING THE STEPS IN COMBINATON OF FORMING A POLYAMINOANTHRAQUINONE SULFATE SUSPENDING THE SULFATE IN AN INERT HIGH BOILING LIQUID AND HEATING THE RESULTING SULFATE TO A TEMPERATURE SUFFICIENTLY HIGH TO CAUSE A MOLECULAR REARRANGEMENT TO FORM THE SULFONATE FROM THE SULFATE, WITH A MINIMUM OF BY-PRODUCTS AND MINIMUM DESTRUCTION OF THE ANTHRAQUINONE MOLECULE. 